PriMera Scientific Engineering (ISSN: 2834-2550)

Review Article

Volume 8 Issue 6

Data Encoding for Distributed and Federated Contact Tracing

Hari TS Narayanan*

May 31, 2026

DOI : 10.56831/PSEN-08-275

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Abstract

In digital contact tracing, a user’s device exchanges proximity data with nearby devices, and this data includes identifiers associated with the user. When a user tests positive, the proximity data stored on their device is analysed to identify others who may have been exposed. Once these individuals are identified, manual contact tracing is initiated for further follow-up. Multiple contact-tracing solutions exist today: some are designed for closed user groups, some for national populations, and others are open systems without clearly defined boundaries. However, these isolated solutions are insufficient for a world with high levels of global mobility. Ideally, a contact-tracing system should be global, interoperable, and capable of supporting seamless mobility across regions. Designing such a system presents several challenges, including scalability. In this study, we propose a proximity-data encoding approach that enables scalable centralized, distributed, and federated contact-tracing architectures. Our federated and distributed models support the coexistence of diverse identifiers and proprietary encryption methods. The federated approach enables user mobility while allowing each country to maintain control over its citizens’ data.

Keywords: Contact Tracing; Encoding; TraceTogether; Exposure Notification; Proximity Identifier; Federated; Distributed; Bluetooth Low Energy; Global mobility

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